Porcine aortic tropoelastin thrombic peptides will be completely sequenced in the coming year using the Solid State Amino Acid Sequencer with detection of PTH derivatives by high precision liquid chromatography. Aortic organ culture studies will be performed to study a gradient of synthesis of tropoelastin which we have discovered in the newborn aorta. Radio-label studies with valine and proline will be used to study the relationships of collagen and elastin synthesis.